components/policy/core/common/forwarding_policy_provider.h

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_POLICY_CORE_COMMON_FORWARDING_POLICY_PROVIDER_H_
   6 #define COMPONENTS_POLICY_CORE_COMMON_FORWARDING_POLICY_PROVIDER_H_
   7
   8 #include "base/basictypes.h"
   9 #include "base/compiler_specific.h"
  10 #include "components/policy/core/common/configuration_policy_provider.h"
  11 #include "components/policy/core/common/policy_namespace.h"
  12 #include "components/policy/policy_export.h"
  13
  14 namespace policy {
  15
  16 // A policy provider that forwards calls to another provider.
  17 // This provider also tracks the SchemaRegistry, and becomes ready after making
  18 // sure the delegate provider has refreshed its policies with an updated view
  19 // of the complete schema. It is expected that the delegate's SchemaRegistry
  20 // is a CombinedSchemaRegistry tracking the forwarding provider's registry.
  21 class POLICY_EXPORT ForwardingPolicyProvider
  22     : public ConfigurationPolicyProvider,
  23       public ConfigurationPolicyProvider::Observer {
  24  public:
  25   // The |delegate| must outlive this provider.
  26   explicit ForwardingPolicyProvider(ConfigurationPolicyProvider* delegate);
  27   virtual ~ForwardingPolicyProvider();
  28
  29   // ConfigurationPolicyProvider:
  30   //
  31   // Note that Init() and Shutdown() are not forwarded to the |delegate_|, since
  32   // this provider does not own it and its up to the |delegate_|'s owner to
  33   // initialize it and shut it down.
  34   //
  35   // Note also that this provider may have a SchemaRegistry passed in Init()
  36   // that doesn't match the |delegate_|'s; therefore OnSchemaRegistryUpdated()
  37   // and OnSchemaRegistryReady() are not forwarded either. It is assumed that
  38   // the |delegate_|'s SchemaRegistry contains a superset of this provider's
  39   // SchemaRegistry though (i.e. it's a CombinedSchemaRegistry that contains
  40   // this provider's SchemaRegistry).
  41   //
  42   // This provider manages its own initialization state for all policy domains
  43   // except POLICY_DOMAIN_CHROME, whose status is always queried from the
  44   // |delegate_|. RefreshPolicies() calls are also forwarded, since this
  45   // provider doesn't have a "real" policy source of its own.
  46   virtual void Init(SchemaRegistry* registry) OVERRIDE;
  47   virtual bool IsInitializationComplete(PolicyDomain domain) const OVERRIDE;
  48   virtual void RefreshPolicies() OVERRIDE;
  49   virtual void OnSchemaRegistryReady() OVERRIDE;
  50   virtual void OnSchemaRegistryUpdated(bool has_new_schemas) OVERRIDE;
  51
  52   // ConfigurationPolicyProvider::Observer:
  53   virtual void OnUpdatePolicy(ConfigurationPolicyProvider* provider) OVERRIDE;
  54
  55  private:
  56   enum InitializationState {
  57     WAITING_FOR_REGISTRY_READY,
  58     WAITING_FOR_REFRESH,
  59     READY,
  60   };
  61
  62   ConfigurationPolicyProvider* delegate_;
  63   InitializationState state_;
  64
  65   DISALLOW_COPY_AND_ASSIGN(ForwardingPolicyProvider);
  66 };
  67
  68 }  // namespace policy
  69
  70 #endif  // COMPONENTS_POLICY_CORE_COMMON_FORWARDING_POLICY_PROVIDER_H_